An incubation experiment with soil water content treatments of 0.15 (W1), 0.20 (W2), and 0.40 (W3) g g-1 soil was carried out for two months to investigate the activities of important enzymes involved in C, N, P, and S cycling in a paddy soil from the Taihu Lake region, China, under waterlogged and aerobic conditions. Compared with air-dried soil, waterlogging resulted in a significant decrease (P (?) 0.05) of fluorescein diacetate (FDA) andβ-D-glucosidase activities, and this effect was enhanced with increasing waterlogging time. Waterlogging also significantly inhibited (P (?)0.05) arylsulfatase as well as alkaline and acid phosphatase activities, but did not decrease the activities with the increase in waterlogging time. Short-term waterlogging did not affect urease activity, but prolonged waterlogging decreased it markedly. In contrast, the aerobic incubation (W1 and W2 treatments) significantly increased (P(?) 0.05) FDA, alkaline phosphatase, andβ-D-glucosidase activities. With aerobic treatments the activities of FDA and alkaline phosphatase increased with incubation time, whereasβ-D-glucosidase activity decreased. A significant difference (P (?) 0.05) was usually observed between the W1 and W2 treatments for the activities of FDA as well as alkaline and acid phosphatase; however,β-D-glucosidase and urease were usually not significant (P(?) 0.05). No activity differences were observed between waterlogging and aerobic incubation for arylsulfatase and urease. An incubation experiment with soil water content treatments of 0.15 (W1), 0.20 (W2), and 0.40 (W3) g g-1 soil was carried out for two months to investigate the activities of important enzymes involved in C, N, P, and S cycling in a paddy soil from the Taihu Lake region, China, under waterlogged and aerobic conditions. Compared with air-dried soil, waterlogging resulted in a significant decrease (P (?) 0.05) of fluorescein diacetate (FDA) Glicosidase activities, and this effect was enhanced with increasing waterlogging time. Waterlogging also significantly inhibited (P (?) 0.05) arylsulfatase as well as alkaline and acid phosphatase activities, but did not decrease the activities with the increase in waterlogging time. In contrast, the aerobic incubation (W1 and W2 treatments) significantly increased (P (?) 0.05) FDA, alkaline phosphatase, and β-D-glucosidase activities. With the prolonged waterlogging decreased it markedly aerobic treatments the activities of FDA and alkaline phosphatase increased with incubation time, while β-D-glucosidase activity decreased. A significant difference (P (?) 0.05) was usually observed between the W1 and W2 treatments for the activities of FDA as well as alkaline and acid phosphatase; however, β-D-glucosidase and urease were usually not significant (P (?) 0.05). No activity differences were observed between waterlogging and aerobic incubation for arylsulfatase and urease.